P.1 

OAR Box 1878 

Prepped by Charmelle Mathews 

Document Number: 

71)11-1-1 

Docket Number: 

A-90-19 

Printed 11/28/2008 1:21:24 PM Sheet 71 of 145 
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and DANIEL OKUN 

d of this volume. 

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A-90-19 

11-1-1 

AIR POLLUTION 

THIRD EDITION 

VOLUME IV 

Engineering Control of 

Air Pollution 

^riiUIJJLJ n 

fPAAIRDOrK-pj 

Edited by 

Arthur C. Stem 

Department of Environmental Sciences and Engineering 

School of Public Health 

University of North Carolina at Chapel Hill 

Chapel Hill, North Carolina 

ACADEMIC PRESS New York San Francisco London 1977 

A Subsidiary of Harcourt Brace Jovanovich, Publishers 

I 5T i 
To Robert C. and Patricia, Mary and Ersi 

COPYRIGHT © 1977, BY ACADEMIC PRESS, INC. 

ALL RIGHTS RESERVED. 

NO PART OF THIS PUBLICATION MAY BE REPRODUCED OR 

TRANSMITTED IN ANY FORM OR BY ANY MEANS, ELECTRONIC 

OR MECHANICAL, INCLUDING PHOTOCOPY, RECORDING, OR ANY 

INFORMATION STORAGE AND RETRIEVAL SYSTEM, WITHOUT 

PERMISSION IN WRITING FROM THF. PUBLISHER. 

ACADEMIC PRESS, INC. 

I l l Filth ATOMIC. New York. New York 10003 

United Kingdom Edition published by 

ACADEMIC PRESS, INC. (LONDON) LTD. 

24/28 Oval Road. London NWI 

Library of Congress Cataloging in Publication Data 

Stern, Arthur Cecil 

Engineering control of air polution. 

(His Air pollution ; v. 4) (Environmental 

sciences) 

Includes bibliographical references and index. 

1. Air-Pollution. 1. Title. II. 

Environmental sciences. 

TD883.S83 1976 voL 4 628.5'3 

ISBN 0-12-666604-0 

Series: 

76-8288 

PRINTED IN THE UNITED STATES OF AMERICA 
338 AMU b IUttr\ 

100 

Time (doys) 

Figure 3. Saturation of coconut shell activated carbon in commercial apple storage (Entiat, Washington). X: Adsorbed water; Q: adsorbed organic vapors. 

well as with increasing molecular weight in a series of compounds of related chemical structure. 

Figure 3, taken from a study of the saturation of activated carbon 

in an apple storage atmosphere at 85% relative humidity and 35°F, 

shows how the initially adsorbed moisture is gradually displaced by the 

adsorbed organic vapors (4). 

C. Oxygenated Adsorbents 

These comprise the silica gels, fuller's, diatomaceous, and other siliceous 

earths, and synthetic zeolites or "molecular sieves." They also, include 

metallic oxides, notably AI2O3, which are even more polar than the siliceous compounds. As previously noted, these materials exhibit greater 

specificity of adsorption than do the activated carbons on the basis of 

preference for more polaT molecules. In addition, the synthetic zeolites 

can be made with specified and uniform pore diameters, which give them 

outstanding properties of adsorbent specificity on the basis of size or 

shape of adsorbate molecules. Even this structural uniqueness, however, 

does not obviate the preference of the adsorbent) for polar rather than 

nonpolar molecules; as a result, these materials will not adsorb organic 

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Inreoslng order of affinity for silica gel 

Figure 4. Relationship between dielectric constant of solvent and affinity for 

silica gel. 

molecules, even of sizes which match their pores, from a moist airstream, 

the water molecules being adsorbed in preference. 

The relationship between the polarity of an adsorbate and its affinity 

for polar adsorbants is shown in Figure 4, which displays various substances in the order of their affinity for silica gel {6). The dielectric constant, which is a good index of electric polarity, closely follows the affinity order. These relationships imply that small, polar molecules, such 

as methanol or formaldehyde, can be effectively removed from dry gas 

streams by strongly polar adsorbents like A1203, and that the saturated 

adsorbent can be effectively regenerated with water. 

D. Adsorbent Impregnations 

. The effectiveness of adsorbent impregnations may be related to any 

of the following modes of action: 

1. The impregnant may be a reagent that chemically converts a pollutant to a harmless or adsoTbable product. As an example, carbon may